Process of refining asphalt base petroleum



Patented Apr. i6, 1935 UNITED STATES PATENT OFFICE PROCESS F REFINiNG ASPHALT BASE PETROLEUM application February i7, i930, serian No. 428,993

3 Claims.

5 oils.

In my co-pending application Serial No. 232,739, led November 12, 1927, I disclosed how oil of the Pennsylvania type, which has a paran, not an asphalt base, might be treated to distill light oils and decolorize simultaneously lubricating cuts. The present application is a continuation in part ofthe above named one and it contemplates the removal of tarry and asphaltic substances from crude petroleum, which is then treated in substantially the same manner as disclosed in the earlier-led case.

Among the objects of the present Vinvention are: the ecient application of an adsorbent to petroleum; the rapid handling of petroleum; and its separation into the desired cuts with the minimum of time and apparatus.

A very important object is to render it possible to produce lubricating oils of the lightest color and best lubricating qualities from crudes hereto-f fore not regarded as being especially suitable for 'the purpose.

Further objects and advantages will be made manifest in the following description and in the accompanying drawing in which an apparatus suitable for carrying out the method of my invention is diagrammatically illustrated. It is to be understood that other apparatus may be employed.

In the drawing, which is a side elevation, partly in section, i represents a conical bottom tank provided with an agitator 2. In a bottom discharge pipe 3 there is a valve 3. The tank i is also provided with a filling pipe 5 for crude oil, having therein a valve 6, and a pipe l for concentrated sulfuric acid, having therein a-valVe t. The dischargepipe 3 connects with a lling pipe 36 of a second agitating tank i2. 'I'o the pipe 35 there is connected a sludge discharge pipe d having therein a valve B. In the pipe 36 near the point where the pipe 9 connects with the latter, there is a valve i i which is located nearer the tank i2 in the pipe 36 than the point where the pipe 9 joins the latter. l

The second agitating tank, denoted by l2, is a substantial duplicate ofthe iirst except that it is provided with aninlet pipe'S'I-for powdered ad-y sorbent. In this pipe is a valve 31a. In the tank i2, 38 is an agitator, 39 the gears for driving the latter, 36 the inlet pipe from the tank l, and d@ the outlet pipe from the tank l2. In the pipe d-there is a valve ma.. The pipe du connects with the suction end of a pump i3.

Connecting the discharge end of the pump t3 with the intake end of the series of heat ex-a changers it is a pipe di. Connecting the outlet 5 end of the series of heat exchangers ld with the intake end of the pipe still l5 is a pipe d5. The pipe still l5 is heated in any suitable manner as by fuel supplied by a burner it. A steam pipe d2 having a Valve d3 is provided at an elbow of l0 the pipe d5 so that steam may be introduced into the oil entering the pipe still. The discharge end of the still i5 is connected to an intermediate portion of the atmospheric column il@ by a pipe d3. Beneath the point` at which the pipe t8 l5 enters the column it, a series of bao plates da and 5@ is disposed in alternating relation so that any liquid discharged through the pipe da into the column l@ must pass in a circuitous route from the point of discharge to the bottom of the column it.

Disposed in the atmospheric column i@ above the point at which the pipe d8 connects thereto are pairs 55 of baille plates d@ and 5t. These pairs 55 arepositioned in spaced relation so as to make room between adjacent pairs for collector pans at. Each of the collector pans ,5s is connected by a pipe 5l to one of the heat exchangers'ift from which pipes 56 lead to suitable distillate storage tanks. Leading from the upper end of theatmospheric column it is a gasoline vapor line td. Connecting the lower end of the atmospheric column l@ to the inlet end of the cooler il! is a pipe il. Connectingthe discharge end of the cooler il to the inlet end of the pump 315 i@ is a pipe t2 into which a solvent pipe t3 connects. The discharge end of the pump it is connected to the iilter press it by a pipe 6i. The

iilter press l@ may be any suitable type of press,

but it is preferably a Sweetland press. Leading from this press is a liquid discharge pipe t5.

'I'he operation of the apparatus above described in carrying out the process of my invention is as follows:

, The process is designed to be continuous, except as to the operation of the first agitating tank or tanks (No. 1). In order to make the opera.- tions following those carried out in the tank i continuous, I prefer to use a battery of acid treating tanks similar to tank i. 50

A suitable charge of crude oil is first run into the tank i through the pipe 5, the agitator started, and a charge of concentrated sulfuric acid is run in from the pipe l. The amount and concentration of the acid win vary with the kind of 55 crude oil worked upon as well as with the time of treatment given. It is therefore impossible to give exact directions as to these factors. The art of asphalt removal from crude by sulfuric acid is quite well understood, however, in the oil refining industry, so persons skilled in the art will well know how to perform the step, Asphalt and tar removal should be approximately complete.

After a suitable period of agitation and settling, the valve II is closed and the valves I 0 and 4 are opened to allow the acid sludge to iiow to Waste through the pipes 3 and 9. As soon as oil begins to flow, the valve I 0 is closed and the valve II is opened. By manual operating of a battery of tanks similar to the tank I a supply of acid-purified, asphalt-free petroleum is intended to be fed continuously into the agitating tank I2. Nothing beyond ordinary skill is necessary to so manipulate a battery of acid treating tanks. Air agitation instead of mechanical agitation may be used in them, and in fact, any standard method of acid treatment may be used in place of the above described process. The oil is not neutralized beforevfurther treatment.

At the same time that a stream of purified oil is .being fed into the agitating tank I2, a continuous supply of a suitable adsorptive agent, which is preferably the acid-treated clay known to the trade as Filtrol but which may be any of the other well known adsorptive clays, is fed into the agitator I2 through the pipe 31. Filtrol is an acid-activated clay made by a process somewhat similar to that disclosed in the United States Patent No. 1,397,113 to Paul W. Prutzman. The agitator 38 is rotated constantly so as to mix the petroleum and the adsorptive agent as these are fed into the agitating tank I2 through the pipe 48 by the pump I3, and discharged through the pipe 4I into the upper end of the series of heat exchangers I4. At this point the valve 43 may be opened and steam forced into the mixture so as to raise the temperature of the mixture and increase the adsorptive tendency which the adsorptive agent has on the petroleum as the temperature of the mixture is gradually raised in its passage through the series of heat exchangers I4.

'Ihe mixture usually enters the first of the heat exchangers I4 at a temperature of approximately 240 F. and leaves `the last of the heat exchangers I4 through which it passes at a temperature of approximately 410 F. The mixture is then conducted through the pipe 45 to the pipe still I 5, where it is raised to a temperature of substantially 750 F., at which temperature it is discharged fromthe pipe 48 into the atmospheric column I6.

'I'he mixture entering the column I6 flows down through-a circuitous path over the baffle plates 49 and 50 and releases all of the lighter fractions of the petroleum so that the residuum which collects in the lower end of the column I6 comprises a mixture of fractions which is termed cylinder stock and which has an a'verage density of 26 B.

The various fractions of petroleum which pass upward through the column I6 in the form of vapors are condensed and cooled in the various pans 56, and owing outward through the heat exchangers I4, effect a rise of the temperature of the petroleum and adsorptive-agent mixture as previously mentioned. Any gasoline vapor which is not condensed in the upper of the pans 56 passes from the column I6 through the gasoline vapor line 60 to a suitable condenser, not shown.

The Various fractions thus condensed in the column I6, in order of decreasing boiling points, may include the following:

The cylinder stock which collects in the lower end of the column I6 flows through the cooler II and the pipe 62 to the pump I8. At this time a suitable solvent is introduced through the pipe 63 into the cylinder stock so that it may be handled more easily by the pump I8 and'lter I9. The pump I8 forces the diluted cylinder stock through the pipe 63 into the filter press I9 which retains the adsorptive clay and permits the purified cylinder stock to be discharged through the pipe 65 which conducts it to a suitable place of storage. When a suiiicient amount of cake has been formed in the filter press I9, the ow of mixture through this filter press is stopped and switched to another similar filter press held in readiness for this purpose. The cake in the filter press I9 is then washed with a suitable solvent so as to remove any of the remaining cylinder stock from the cake. Suitable provision may also be made for blowing the cake in the press with either air or steam after removing the retained oil so as to drive out the excess of solvent and dry the cake. Thereafter the filter press is opened and the cake removed and conveyed by any suitable means, such as a belt conveyor, to the extraction equipment where the oil can be recovered and then to the reactivating house where the clay is reactivated so as to again be suitable for use in the above described process.

As stated above, this process has been particularly successful with the use of Filtrol, which is a product that has been chemically treated so that there are no elements therein to cause any chemical reaction when acid is added to it. Therefore, no sulphates are formed as is the case when acid is added to a. natural or untreated earth.

When Filtrol is used as the adsorptive agent, it is possible to add a slight amount of acid in 'the reactivating process so that the Filtrol acts as a carrier for the acid in an unaltered state. Thus, due to the enormous surfaces in the Filtrol on which the acid is carried in a thin film, there is very powerful action on the oil, even when an extremely small amount of acid has been added to the Filtrol,

Another great advantage of using the acid in this manner is that it acts upon the oil without being given up by the Filtrol so that neutralization of the final oil product is unnecessary.

It is also desired to point out that the impure substances are absorbed by the adsorptive clay before the vapors are discharged from the mixture of oil and clay in the column I6, so that fractions condensed in the pans 56 of the column I6 are already purified and further treatment of these is therefore unnecessary.

A novel and very important feature of my invention is thus seen to be the treatment with an adsorptive agent of the oil being distilled in both its liquid and vapor phases. Another novel feature of importance is treating these liquid and vapor phases as they are interchanging with each other by alternate vaporization and condensation. The purification of the various products into which the oil is divided is thus accomplished concurrently with the distillation and with an efficiency and purity of productl hitherto unknown.

While I have described a continuous process I do not limit myself thereto since my invention can be operated as a batch process by anyone skilled in the art who is in possession of the information communicated herein.

It will be noted that my process depends for its eiiiciency upon the fact that certain adsorptive materials, of which Filtrol is a good example, have a selective ailinity for certain vaporizable impurities commonly found in petroleum distillates. If an oil containing these impurities is mixed with such a material, the impurities are adsorbed (or possibly absorbed) in the material and are held therein even if the mixture is subjected`to temperatures at which the impurities are normally vaporizable. It is then possible by spreading the mixture in a film thin enough to eliminate any substantial static pressure on the vapors, to cause a substantial evolution of vapors free from said impurities.

I claim as my invention:

l. A process of treating crude oil having tar and asphalt content which consists in eliminating the tar and asphalt content by agitating such an oil with concentrated sulphuric acid and separating the oil from the sludge produced thereby, mixing decolorizing clay with the oil, passing the resultant mixture through a heating zone and heating the same to a temperature sufficient to vaporize lighter fractions of the crude oil, introducing the mixture to a fractionating zone at a poi/nt substantially above the bottom thereof whereby unvaporized portions of the mixture descend toward the bottom of said fractionating zone and released vapors ascend toward the top thereof, condensing heavier fractions of the released vapors in the portion of said fractionating zone above the point of introduction of the mixture thereto, separately withdrawing the condensed fractions from the fractionating zone, removing lighter. fractions of the released vapors from the top of said fractionating Zone and subjecting the same to condensation, withdrawing the mixture of unvaporized lubricating stock and clay from the bottom of said fractionating zone,

andi separating the clay from said lubricating stock.

2.' A process of refining hydrocarbon oil containing asphaltic. substances for the production of lubricating stock therefrom which comprises agitating such an oil with concentrated sulphuric acid, separating the oil from the sludge produced thereby, mixing a clay adsorptive with said oil, passing the resultant mixture through a heating zone and heating the same to a temperaturesufcient to vaporize lighter fractions of the crude oil, introducing the mixture to a fractionating Zone at a point substantially above the bottom thereof whereby unvaporized portions of the mixture descend toward the bottom of said fractionating zone and released vapors ascend toward the top thereof, condensing fractions of the released vapors heavier than gasoline in the portion of said fractionating zone above the point of introduction of the heated mixture thereto, separately withdrawing the condensed fractions from the fractionating zone, removing gasoline vapors from the top of said fractionating zone and subjecting the same to condensation, withdrawing the mixture of unvaporized lubricating stock and clay from the bottom of said fractionating zone, and separating the clay from said lubricating stock.

3. A process of refining hydrocarbon oil containing asphaltic substances for the production of lubricating stock therefrom which comprises agitating such an oil with concentrated sulphuric acid, separating the oil from the sludge produced thereby, mixing a clay' adsorptive with said oil, passing the resultant mixture through a heating zone and heating the same sufficiently to vaporize lighter fractions of the oil, introducing the mixture to a separating zone at a point substantially above the bottom thereof, passing the mixture downwardly toward the bottom of said separating zone in relatively thin layers to assist the release of vapors therefrom, condensing released vapors' in the portion of said separating zone above the point of introduction of the mixture thereto, separately withdrawing condensed vapors from the separating zone, removing the mixture of unvaporized lubricating stock and clay from the lower portion of said separatingl zone, and separating the clay from said lubricating stock.

WALTER S. BAYLIS. 

